Yeah I've got the base model too. It does get pretty toasty and stutters after a while if I have it on extended highlights and there's a lot of them.
I tend to use key highlights mostly which helps and I don't run quite as many leagues as yourself. I would imagine the results of the other leagues is also being calculated in the background whilst you're playing your game which may put extra pressure on.
Like I said I don't see it as a massive problem, mainly due to my expectations from a passively cooled system but I do hope like yourself that they can fine tune it for FM24 and beyond